首先创建一个路径，然后配置闪回去大小和位置，mount状态下flashback为on，最后打开数据库。
[oracle@ocm1 ~]$ mkdir /home/oracle/flash
[oracle@ocm1 ~]$ sqlplus "/as sysdba"
SQL*Plus: Release 10.2.0.1.0 - Production on Fri Mar 21 14:13:55 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
SQL> show parameter db_recovery_file_dest
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string
db_recovery_file_dest_size big integer 0
SQL> alter system set db_recovery_file_dest_size=4g scope=spfile;
System altered.
SQL> alter system set db_recovery_file_dest=‘/home/oracle/flash‘ scope=spfile;
System altered.
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.
Total System Global Area 524288000 bytes
Fixed Size 1220360 bytes
Variable Size 176161016 bytes
Database Buffers 343932928 bytes
Redo Buffers 2973696 bytes
Database mounted.
SQL> alter database flashback on;
Database altered.
SQL> alter database open;
Database altered.
SQL> select flashback_on from v$database;
FLASHBACK_ON
------------------
YES
SQL>
SQL> show parameter recovery
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string /home/oracle/flash
db_recovery_file_dest_size big integer 4G
recovery_parallelism integer 0
